void DestroyPinnedShadow()
{
if (mPinnedSection != null)
{
mRecycleSection = mPinnedSection;
mPinnedSection = null;
}
}
/** Create shadow wrapper with a pinned view for a view at given position */
void CreatePinnedShadow(int position)
{
// try to recycle shadow
PinnedSection pinnedShadow = mRecycleSection;
mRecycleSection = null;
// create new shadow, if needed
if (pinnedShadow == null)
{
pinnedShadow = new PinnedSection();
}
// request new view using recycled view, if such
View pinnedView = Adapter.GetView(position, pinnedShadow.ViewHolder, this);
// read layout parameters
LayoutParams layoutParams = (LayoutParams)pinnedView.LayoutParameters;
if (layoutParams == null)
{
layoutParams = (LayoutParams)GenerateDefaultLayoutParams();
pinnedView.LayoutParameters = layoutParams;
}
MeasureSpecMode heightMode = MeasureSpec.GetMode(layoutParams.Height);
int heightSize = MeasureSpec.GetSize(layoutParams.Height);
if (heightMode == MeasureSpecMode.Unspecified)
{
heightMode = MeasureSpecMode.Exactly;
}
int maxHeight = Height - ListPaddingTop - ListPaddingBottom;
if (heightSize > maxHeight)
{
heightSize = maxHeight;
}
// measure & layout
int ws = MeasureSpec.MakeMeasureSpec(Width - ListPaddingLeft - ListPaddingRight, MeasureSpecMode.Exactly);
int hs = MeasureSpec.MakeMeasureSpec(heightSize, heightMode);
pinnedView.Measure(ws, hs);
pinnedView.Layout(0, 0, pinnedView.MeasuredWidth, pinnedView.MeasuredHeight);
mTranslateY = 0;
// initialize pinned shadow
pinnedShadow.ViewHolder = pinnedView;
pinnedShadow.Position = position;
pinnedShadow.ID = Adapter.GetItemId(position);
// store pinned shadow
mPinnedSection = pinnedShadow;
}